Misidentification of two Brazilian triatomes, Triatoma arthurneivai and Triatoma wygodzinskyi, revealed by geometric morphometrics

Triatoma arthurneivai Lent & Martins and Triatoma wygodzinskyi Lent (Hemiptera: Reduviidae) are two Brazilian species found in the sylvatic environment. Several authors may have misidentified T. arthurneivai and consequently published erroneous information. This work reports the use of geometric morphometric analysis on wings in order to differentiate T. arthurneivai and T. wygodzinskyi, and thus to detect possible misidentifications. Triatomines collected from the field in the states of Minas Gerais and Sao Paulo, and from laboratory colonies, were used. Analyses show a clear differentiation between specimens of T. arthurneivai and T. wygodzinskyi. This indicates that T. arthurneivai populations from Sao Paulo state were misidentified and should be considered as T. wygodzinskyi. This study also suggests that T. arthurneivai is an endemic species from Serra do Cipo, Minas Gerais state.

Morphology, molecular phylogeny, and taxonomic inconsistencies in the study of Bradypus sloths (Pilosa: Bradypodidae)

This study focuses on morphological and molecular data analyses, misidentifications, and phylogenetic inconsistencies regarding Bradypus variegatus (the brown-throated sloth) and B. tridactylus (the pale-throated sloth). Misidentifications were recorded on 75 of 313 museum specimens of Bradypus. Almost 90% of the misidentified specimens were B. variegatus from north-central Brazil, erroneously attributed to B. tridactylus. These misidentified specimens are reported in taxonomic reviews as the southernmost records of B. tridactylus. A history of confusing nomenclature regarding sloth species exists, and these particular misidentifications could be attributable to the similarity in face and throat color between B. variegatus from north-central Brazil and B. tridactylus. The molecular phylogeny of morphologically confirmed sloth specimens exhibits 2 monophyletic lineages representing B. variegatus and B. tridactylus. The split time between these 2 lineages was estimated at 6 million years ago (mya), contradicting previous studies that estimated this divergence to be 0.4 mya. Taxonomic inconsistencies were detected when comparing the molecular phylogeny to previously published DNA sequences ascribed to B. tridactylus. Misidentification or introgression could underlie such phylogenetic incongruities. Regardless of their causes, these discrepancies lead to misstatements regarding geographic distribution, phylogeny, and taxonomy of B. variegatus and B. tridactylus.

An old taxonomic dilemma: the identity of the western south Atlantic lebranche mullet (Teleostei: Perciformes: Mugilidae)

The identification of the lebranche mullet in the western south Atlantic has long been problematical. In most recent works either Mugil liza Valenciennes and M. platanus Gunther, 1880 or M. liza and M. cephalus Linnaeus, 1758 were recognized from the region and more rarely the occurrence of only one species has been proposed but without sufficient morphological, biochemical or molecular data to allow the designation of the taxonomically appropriate name. Analysis of meristic and morphometric data taken from samples collected from Venezuela to Argentina, clearly indicates that there is only one species of lebranche mullet in the Caribbean Sea region and the Atlantic coast of South America and that Mugil liza is the appropriate name. The comparison of the combined data from all the samples of M. liza with the data taken from one sample of M. cephalus that originated in the Mediterranean, the possible locality from which type specimens were collected (Eschmeyer and Fricke, 2009), revealed significant differences indicating that they are different species. It is also suggested that individuals from the western north Atlantic identified as M. cephalus might represent a population of M. liza in this region.

A systematic revision of Goniosomatinae (Arachnida : Opiliones : Gonyleptidae), with a cladistic analysis and biogeographical notes

Goniosomatine harvestmen have strongly armed pedipalps, generally large bodies and, commonly, very long legs (sometimes more than 20 cm), and are distributed in the Brazilian Atlantic forest, from southern Bahia to Santa Catarina. Since they are conspicuous animals and individuals of some species tend to concentrate in caves (and also under rock boulders), they have been (and still are) the target of several studies, especially those focusing on reproductive and defensive behavior, population ecology, physiology, chromosomes, etc. In spite of their importance for biological studies (some species constitute important and frequently used models for these studies), the taxonomy of Goniosomatinae has faced some problems, including misidentification, a large number of undescribed species and the lack of a phylogenetic hypothesis for the relationships among its species (which would allow evolutionary studies to be made). The last taxonomic changes in the subfamily were made 60 years ago. Considering a taxonomic revision and cladistic analysis of the subfamily to be of paramount importance, the main scope of the present paper is to provide a cladistic analysis and taxonomic revision of the species of Goniosomatinae and a new arrangement of genera (and species). The main taxonomic changes are given as follows. Six genera are recognised within the subfamily: Goniosoma; the newly described genus Pyatan; the reestablished genera Serracutisoma, Heteromitobates and Mitogoniella; and Acutisoma. New generic synonyms include: Glyptogoniosoma = Goniosomella = Lyogoniosoma = Metalyogoniosoma = Xulapona = Goniosoma, Acutisomelloides = Pygosomoides = Spelaeosoma = Serracutisoma; and Acutisomella = Heteromitobates. Newly described species include: Goniosoma capixaba; G. apoain; Pyatan insperatum DaSilva, Stefanini-Jim & Gnaspini; Serracutisoma pseudovarium; S. fritzmuelleri; S. guaricana; Heteromitobates anarchus; H. harlequin; H. alienus; Mitogoniella taquara; M. unicornis; and Acutisoma coriaceum. New combinations include: Goniosoma macracanthum (Mello-Leitao, 1922); G. unicolor (Mello-Leitao, 1932); G. carum (Mello-Leitao, 1936); Serracutisoma proximum (Mello-Leitao, 1922); S. banhadoae (Soares & Soares, 1947); S. molle (Mello-Leitao, 1933); S. thalassinum (Simon, 1879); S. catarina (Machado, Pinto-da-Rocha & Ramires, 2002); S. inerme (Mello-Leitao, 1927); S. spelaeum (MelloLeitao, 1933); Heteromitobates inscriptus (Mello-Leitao, 1922); H. albiscriptus (Mello-Leitao, 1932); Mitogoniella modesta (Perty, 1833); and M. badia (Koch, 1839). Reestablished combinations include: Mitogoniella indistincta MelloLeitao, 1936 and Acutisoma longipes Roewer, 1913. New speci. c synonyms include: Acutisomella cryptoleuca = Acutisomella intermedia = Goniosoma junceum = Goniosoma patruele = Goniosoma xanthophthalmum = Metalyogoniosoma unum = Goniosoma varium, Goniosoma geniculatum = Goniosoma venustum; Goniosomella perlata = Progoniosoma minense = Goniosoma vatrax, Glyptogoniosoma perditum = Progoniosoma cruciferum = Progoniosoma tijuca = Goniosoma dentipes; Leitaoius iguapensis = Leitaoius viridifrons = Serracutisoma proximum; Acutisoma marumbicola = Acutisoma patens = Serracutisoma thalassinum; Progoniosoma tetrasetae = Serracutisoma inerme; and Acutisoma monticola = Leitaoius nitidissimus = Leitaoius xanthomus = Mitogoniella mutila = Acutisoma longipes. The following species are considered species inquirenda: Goniosoma lepidum Gervais, 1844; G. monacanthum Gervais, 1844; G. obscurum Perty, 1833; G. versicolor Perty, 1833; and Mitogoniella badia (Koch, 1839). The monotpic genus Goniosomoides Mello-Leitao, 1932 (and its species, G. viridans Mello-Leitao, 1932) is removed from Goniosomatinae and considered incertae sedis.

The catalytic and other residues essential for the activity of the midgut trehalase from Spodoptera frugiperda

Trehalase (EC 3.2.1.28) hydrolyzes only alpha, alpha`- trehalose and is present in a variety of organisms, but is most important in insects and fungi. Crystallographic data showed that bacterial trehalase has 0312 and E496 as the catalytical residues and three Arg residues in the active site. Those residues have homologous in all family 37 trehalases including Spodoptera frugiperda trehalase (0322, E520, R169, R227, R287). To test the role of these residues, mutants of trehalase were produced. All mutants were at least four orders of magnitude less active than wild type trehalase and no structural difference between these mutants and wild type enzyme were discernible by circular dichroism. D322A and E520 pH-activity profile lacked the alkaline arm and the acid arm, respectively, suggesting that D322 is the acid and E520 the basic catalyst. Azide increases E520A activity three times, confirming its action as the basic catalyst. Taking into account the decrease in activity after substitution for alanine residue, the three arginine residues are as important as the catalytical ones to trehalase activity. This clarifies the previous misidentification of an Arg residue as the acid catalyst. As far as we know, this is the first report on the functional identification residues important for trehalase activity. (C) 2010 Elsevier Ltd. All rights reserved.